Although influenced by several factors and other methods to determine the bulk density of the soil, you must first know the same to determine the method that you should apply. If you have a free soil of stones, you can apply the method of the cylinder. If your soil has stones, you must apply another method, known as the pit method. Then I leave a post in which you can read both methods and remain at disposal for further explanation. regards
I agree with the comments above. But in addition, you could burn or dessicate the material to get a dry weight - although a different measure, this often correlates closely with bulk.
In addition to above comments, the core method is the simplest and reliable method even if there is stone. You can calculate the bulk density of the soil by excluding the volume and mass of stones by using the following formula.
Bulk density = (Oven dry mass of the sample - dry mass of the stone) /(volume of a corer - (oven dry of stone/density of stone which is ~ 2.6)).
In my humble opinion, soil core collected with cylinder is the most popular, and is easier than other methodologies. Using a correct cylinder design and a good sampler, your results will be very accurate.
Using soil cylinder, you can determine also Hydraulic conductivity, Air permeability, particle density and soil moisture content with the same sample, thinking in get deep in your research project.
As mentioned above, you can correct your bulk density value if you have percentage of stone of your sample.
I agree with Manuel comments. You may also collect soil cores from the field at different moisture contents and see the relationships. The bulk density values though are based on oven dried mass of soil but in field the bulk density values below the field moisture content are useful which influence all the processes occurring in the soils.
I think the best method is the cylinder method as describe above.
In case is not possible due to stone, hold method can be use to estimate soil volume extract with soil sample ( with water and plastic bag) and quantify the soil sample in lab.
Manuel E Camacho , Thanks for the answer and the additional info provided as well. Can you please develop a little bit more on the other parameters (hydraulic conductivity, soil moisture, air permeability and particle density) that are possible to be measured with the core cyclinder method? Do you have any good practice reference to share with me? thanks
There you will have access to the methods for bulk and particle density, hydraulic conductivity and air permeability, using soil core cylinders.
If you cannot access the PDF's, please let me know.
As well I attached are couple of papers of hydraulic properties measured on forest and forestry, and two PDF with Eijkelkamp equipments to measure soil porosity, and air permeabilty through soil core cylinders.